1. Field of the Invention
This invention relates to apparatus for revitalizing tennis balls. More specifically, this invention relates to means for increasing the pressure inside a tennis ball for the purpose of restoring bounce quality to a used tennis ball similar to the bounce quality it had when new.
2. Description of the Prior Art
In the manufacture of tennis balls, the inside of the rubber shell of the ball is often pressurized with fluid pressure in the range of 10 to 12 pounds per square inch. This pressure contributes substantially to the bounce of the ball over and above the natural resilience of the rubber of the ball. To assure that tennis balls arrive at the marketplace still with the desired fluid pressure, balls are packaged in a metal can under pressure approximating the pressure within the ball so that there is an equilibrium across the ball shell. There is thus little or no tendency for pressure within the ball to escape through the pores of the ball as long as the ball is in its package. After the opening of its pressurized can, the ball is only under atmospheric pressure and soon loses its internal pressure. One explanation for this loss is that as the ball ages, it expands slightly and pores in the rubber open up thus permitting internal pressure to leak out. Losing its pressure, the ball correspondingly looses its original bouncing quality and becomes a "dead" ball.
Attempts have been made to provide devices to help maintain a tennis ball at its original bouncing quality. Such devices include pressureable containers simulating the original pressurized can and into which the balls are put after play and during storage. Also, clamps have been offered comprising hemispheres closed tightly about the ball to inhibit its expansion during storage on the theory that inhibiting expansion will delay development of leaking pores in the rubber shell of the ball.
Prior attempts to prolong the life of tennis balls have been troublesome and have generally not been effective. They have not offered the possibility of immediately revitalizing a "dead" ball.